216 Ozone and the Atmosphere. 



OZONOSCOPES WITH HYDEOGEN PEEOXIDE. 



OZONOSCOPES. 



FIBST SERIES. 



SEGOKD SERIES. 



KI 



Light yellow (7) 

 Paint lilac (8) 

 Light brown (2) 

 " (3) 

 ? (9) 

 Faint brown (4) 

 Bed (6) 



? 



Light brown (5) 

 Somewhat bleached (10) 

 Blue (fine color) (1) 



Yellow (10) 

 Intense blue (6) 

 Very dark brown (1) 

 Dark brown (2) 

 Brown to blue (3) 



" " - (4) 

 Beddened (8) 

 Rluish (9) 

 Unchanged 

 (Not tried) 

 Bleached to gray (7) 

 Beautiful blue (5) 





Moffat 









Thallium 











The hydrogen peroxide used in the first series was made 

 from hydrated peroxide of barium, by decomposing with hydro" 

 chloric acid. The papers were suspended for about 15 hours 

 over a solution containing 0.0044 grm. of the peroxide. Since 

 the solution, prepared in this way, contained a little acid which 

 had not been entirely removed, and this acid, by reacting with 

 the peroxide, might liberate chlorine, — a second series of trials 

 was instituted. In this, the solution had been prepared by de- 

 composing with carbonic acid, and contained 0. 5 p. c. of the 

 peroxide. The ozonoscopes were exj^osed during a like interval. 



In a third series, the papers being exposed for 48 hours dur- 

 ing day and night, over a solution containing 0. 2 p. c. hydrogen 

 peroxide, Moffat's turned to a brown color, Osann's became 

 brownish-blue,guaiacum a beautiful light blue,alizarine reddened, 

 Houzeau's test apparently changed somwhat in the direction of 

 blue and afterwards was partly bleached, cadmium test became 

 dark-blue, potassium iodide quite white and damp,lead sulphide 

 bleached to gray, silver was not affected. It is probable that the 

 potassium iodide was decomposed, but became colorless again by 

 conversion into iodate. This supposition was strengthened by 

 the damp condition of the paper. The thallium test remained 

 white, thallium peroxide undergoing reduction in contact with 

 hydrogen peroxide, — water and oxygen being liberated. 



Action of Ozone upon the Coloring Matter of Flowers : — 

 In connection with the use of organic coloring matters as 

 ozonoscopes, experiments were made as to the action of ozone 



